The present invention relates to surfactant compositions and, more particularly, to flowable or pumpable compositions containing sulfated alkoxylated alcohols.
Sulfated alkoxylated alcohols (ES) are used in many detergent applications. Substantially water free sulfated alkoxylated alcohols, particularly those containing greater than 5 moles of ethylene oxide per mole of alcohol, range from viscous liquids to gel like materials and are generally unpumpable or non-fluid at normal handling temperatures in the range of 110.degree. to 120.degree. F. For ease of shipment and handling, it is desired that the ES materials be formulated into a fluid or pumpable form so that they can more easily and economically be converted into detergent end product. Generally speaking, aqueous ES compositions containing 25-30% by weight of the ES material in water are fluid. However, these "low active" liquid compositions are undesirable for several reasons. For one, because the concentration of the ES is so low, it requires excessive freight costs since more of the aqueous composition must be shipped in order to obtain the desired quantity of the active ingredient, i.e. the ES material. Additionally, since the compositions contain such large quantities of water, there are excessive energy costs in connection with spray drying to remove the water to obtain solids for incorporation into detergent powders. There are also restrictions upon the amount of other water containing ingredients used in formulating a mixture for spray drying to a detergent powder which make such "low active" compositions undesirable.
Preferably, an ES composition which contains from about 30 to about 50% by weight of the sulfated alkoxylated alcohol would be desirable since it would overcome the disadvantages discussed above with respect to the low active compositions. Unfortunately, in the past it has been found that attempts to formulate compositions containing in excess of about 30% by weight ES material resulted in a material that yielded either a rigid gel or a highly viscous fluid which, in any event, was essentially unpumpable or non-fluid under normal handling conditions, i.e. from about 110.degree. F. to 120.degree. F.
It is known to add lower alcohols, e.g. methanol, ethanol, etc., to high active ES solutions in order to reduce the viscosity and render them fluid or pumpable. However, the addition of such lower alcohols is undesirable since, in the spray drying operation to recover the ES product, the alcohols, which are vented from the spray dryer, must be recovered to minimize potential environmental problems meaning that the spray drying operation becomes more expensive.